boto Count number of versions for a specific object - boto

I have a s3 bucket with versions on and a key with a number of version. I was wondering if there's an efficient way of finding the number of versions of a particular key that are in the bucket.
Here's the only way I know of
version_count = list(bucket.list_versions().__iter__())
Is this information anywhere else?
It would be really nice if I could get this information through deleting a version but haven't found anything in my searching.

The only way to find all of the versions of an object is to list the versions. However, you need to be careful when listing versions because the list of objects returned could also include DeleteMarkers which should not be counted.
I found this worked:
import boto
from boto.s3.key import Key
c = boto.connect_s3()
bucket = c.lookup('mybucket')
versions = [v for v in bucket.list_versions('myversionedobject') if isinstance(v, Key)]
The variable versions will now contain a list of actual versions and, obviously, doing a len() on that list will give you the number of versions. If there is an easier way to do it, I'm not aware of it.

Related

Output index of ELKI

I am using ELKI to cluster data from CSV file
I use
-resulthandler ResultWriter
-out folder/
to save the outputdata
But as an output I have some strange indexes
ID=2138 0.1799 0.2761
ID=2137 0.1797 0.2778
ID=2136 0.1796 0.2787
ID=2109 0.1161 0.2072
ID=2007 0.1139 0.2047
The ID is more than 2000 despite I have less than 100 training samples
DBIDs are internal; the documentation clearly says that you shouldn't make too much assumptions on them because their implementation may change. The only reason they are written to the output at all is because some methods (such as OPTICS) may require cross-referencing objects by this unique ID.
Because they are meant to be unique identifiers, they are usually continuously incremented. The next time you click on "run" in the MiniGUI, you will get the next n IDs... so clearly, you clicked run more than once.
The "Tips & Tricks" in the ELKI DBID documentation probably answer your underlying question - how to use map DBIDs to line numbers of your input file. The best way is to if you want to have object identifiers, assign object identifiers yourself by using an identifier column (and configuring it to be an external identifier).
For further information, see the documentation: https://elki-project.github.io/dev/dbids

Rest API design with multiple unique ids

Currently, we are developing an API for our system and there are some resources that may have different kinds of identifiers.
For example, there is a resource called orders, which may have an unique order number and also have an unique id. At the moment, we only have URLs for the id, which are these URLs:
GET /api/orders/{id}
PUT /api/orders/{id}
DELETE /api/orders/{id}
But now we need also the possibility to use order numbers, which normally would result into:
GET /api/orders/{orderNumber}
PUT /api/orders/{orderNumber}
DELETE /api/orders/{orderNumber}
Obviously that won't work, since id and orderNumber are both numbers.
I know that there are some similar questions, but they don't help me out, because the answers don't really fit or their approaches are not really restful or comprehensible (for us and for possible developers using the API). Additionally, the questions and answers are partially older than 7 years.
To name a few:
1. Using a query param
One suggests to use a query param, e.g.
GET /api/orders/?orderNumber={orderNumber}
I think, there are a lot of problems. First, this is a filter on the orders collections, so that the result should be a list as well. However, there is only one order for the unique order number which is a little bit confusing. Secondly, we use such a filter to search/filter for a subset of orders. Additionally, a query params is some kind of a second-class parameter, but should be first-class in this case. This is even a problem, if I the object does not exist. Normally a get would return a 404 (not found), but a GET /api/orders/?orderNumber=1234 would be an empty array, if the order 1234 does not exist.
2. Using a prefix
Some public APIs use some kind of a discriminator to distinguish between different types, e.g. like:
GET /api/orders/id_1234
GET /api/orders/ordernumber_367652
This works for their approach, because id_1234 and ordernumber_367652 are their real unique identifiers that are also returned by other resources. However, that would result in a response object like this:
{
"id": "id_1234",
"ordernumber": "ordernumber_367652"
//...
}
This is not very clean, because the type (id or order number) is modelled twice. And apart from the problem of changing all identifiers and response objects, this would be confusing, if you e.g. want to search for all order numbers greater than 67363 (thus, there is also a string/number clash). If the response does not add the type as a prefix, a user have to add this for some request, which would also be very confusing (sometime you have to add this and sometimes not...)
3. Using a verb
This is what e.g. Twitter does: their URL ends with show.json, so you can use it like:
GET /api/orders/show.json?id=1234
GET /api/orders/show.json?number=367652
I think, this is the most awful solution, since it is not restful. Furthermore, it has some of the problems that I mentioned in the query param approach.
4. Using a subresource
Some people suggest to model this like a subresource, e.g.:
GET /api/orders/1234
GET /api/orders/id/1234 //optional
GET /api/orders/ordernumber/367652
I like the readability of this approach, but I think the meaning of /api/orders/ordernumber/367652 would be "get (just) the order number 367652" and not the order. Finally, this breaks some best practices like using plurals and only real resources.
So finally, my questions are: Did we missed something? And are there are other approaches, because I think that this is not an unusual problem?
to me, the most RESTful way of solving your problem is using the approach number 2 with a slight modification.
From a theoretical point of view, you just have valid identification code to identify your order. At this point of the design process, it isn't important whether your identification code is an id or an order number. It's something that uniquely identify your order and that's enough.
The fact that you have an ambiguity between ids and numbers format is an issue belonging to the implementation phase, not the design phase.
So for now, what we have is:
GET /api/orders/{some_identification_code}
and this is very RESTful.
Of course you still have the problem of solving your ambiguity, so we can proceed with the implementation phase. Unfortunately your order identification_code set is made of two distinct entities that share the format. It's trivial it can't work. But now the problem is in the definition of these entity formats.
My suggestion is very simple: ids will be integers, while numbers will be codes such as N1234567. This approach will make your resource representation acceptable:
{
"id": "1234",
"ordernumber": "N367652"
//...
}
Additionally, it is common in many scenarios such as courier shipments.
Here is an alternate option that I came up with that I found slightly more palatable.
GET /api/orders/1234
GET /api/orders/1234?idType=id //optional
GET /api/orders/367652?idType=ordernumber
The reason being it keeps the pathing consistent with REST standards, and then in the service if they did pass idType=orderNumber (idType of id is the default) you can pick up on that.
I'm struggling with the same issue and haven't found a perfect solution. I ended up using this format:
GET /api/orders/{orderid}
GET /api/orders/bynumber/{orderNumber}
Not perfect, but it is readable.
I'm also struggling with this! In my case, i only really need to be able to GET using the secondary ID, which makes this a little easier.
I am leaning towards using an optional prefix to the ID:
GET /api/orders/{id}
GET /api/orders/id:{id}
GET /api/orders/number:{orderNumber}
or this could be a chance to use an obscure feature of the URI specification, path parameters, which let you attach parameters to particular path elements:
GET /api/orders/{id}
GET /api/orders/{id};id_type=id
GET /api/orders/{orderNumber};id_type=number
The URL using an unqualified ID is the canonical one. There are two options for the behaviour of non-canonical URLs: either return the entity, or redirect to the canonical URL. The latter is more theoretically pure, but it may be inconvenient for users. Or it may be more useful for users, who knows!
Another way to approach this is to model an order number as its own thing:
GET /api/ordernumbers/{orderNumber}
This could return a small object with just the ID, which users could then use to retrieve the entity. Or even just redirect to the order.
If you also want a general search resource, then that can also be used here:
GET /api/orders?number={orderNumber}
In my case, i don't want such a resource (yet), and i could be uncomfortable adding what appears to be a general search resource that only supports one field.
So basically, you want to treat all ids and order numbers as unique identifiers for the order records. The thing about unique identifiers is, of course, they have to be unique! But your ids and order numbers are all numeric; do their ranges overlap? If, say, "1234" could be either an id or an order number, then obviously /api/orders/1234 is not going to reference a unique order.
If the ranges are unique, then you just need discriminator logic in the handler code for /api/orders/{id}, that can tell an id from an order number. This could actually work, say if your order numbers have more digits than your ids ever will. But I expect you would have done this already if you could.
If the ranges might overlap, then you must at least force the references to them to have unique ranges. The simplest way would be to add a prefix when referring to an order number, e.g. the prefix "N". So that if the order with id 1234 has order number 367652, it could be retrieved with either of these calls:
/api/orders/1234
/api/orders/N367652
But then, either the database must change to include the "N" prefix in all order numbers (you say this is not possible) or else the handler code would have to strip off the "N" prefix before converting to int. In that case, the "N" prefix should only be used in the API calls - user facing data-entry forms should not expose it! You can't have a "lookup by any identifier" field where users can enter either id or order number (this would have a non-uniqueness problem anyway.) Instead, you must have separate "lookup by id" and "lookup by order number" options. Then, you should be able to have the order number input handler automatically add the "N" prefix before submitting to the API.
Fundamentally, this is a problem with the database design - if this (using values from both fields as "unique identifiers") was a requirement, then the database fields should have been designed with this in mind (i.e. with non-overlapping ranges) - if you can't change the order number format, then the id format should have been different.

Simperium Data Dictionary or Decoder Ring for Return Value on "all" call?

I've looked through all of the Simperium API docs for all of the different programming languages and can't seem to find this. Is there any documentation for the data returned from an ".all" call (e.g. api.todo.all(:cv=>nil, :data=>false, :username=>false, :most_recent=>false, :timeout=>nil) )?
For example, this is some data returned:
{"ccid"=>"10101010101010101010101010110101010",
"o"=>"M",
"cv"=>"232323232323232323232323232",
"clientid"=>"ab-123123123123123123123123",
"v"=>{
"date"=>{"o"=>"+", "v"=>"2015-08-20T00:00:00-07:00"},
"calendar"=>{"o"=>"+", "v"=>false},
"desc"=>{"o"=>"+", "v"=>"<p>test</p>\r\n"},
"location"=>{"o"=>"+", "v"=>"Los Angeles"},
"id"=>{"o"=>"+", "v"=>43}
},
"ev"=>1,
"id"=>"abababababababababababababab/10101010101010101010101010110101010"}
I can figure out some of it just from context or from the name of the key but a lot of it is guesswork and trial and error. The one that concerns me is the value returned for the "o" key. I assume that a value of "M" is modify and a value of "+" is add. I've also run into "-" for delete and just recently discovered that there is also a "! '-'" which is also a delete but don't know what else it signifies. What other values can be returned in the "o" key? Are there other keys/values that can be returned but are rare? Is there documentation that details what can be returned (that would be the most helpful)?
If it matters, I am using the Ruby API but I think this is a question that, if answered, can be helpful for all APIs.
The response you are seeing is a list of all of the changes which have occurred in the given bucket since some point in its history. In the case where cv is blank, it tries to get the full history.
You can find some of the details in the protocol documentation though it's incomplete and focused on the WebSocket message syntax (the operations are the same however as with the HTTP API).
The information provided by the v parameter is the result of applying the JSON-diff algorithm to the data between changes. With this diff information you can reconstruct the data at any given version as the changes stream in.

How to enumerate the keys and values of a record in AppleScript

When I use AppleScript to get the properties of an object, a record is returned.
tell application "iPhoto"
properties of album 1
end tell
==> {id:6.442450942E+9, url:"", name:"Events", class:album, type:smart album, parent:missing value, children:{}}
How can I iterate over the key/value pairs of the returned record so that I don't have to know exactly what keys are in the record?
To clarify the question, I need to enumerate the keys and values because I'd like to write a generic AppleScript routine to convert records and lists into JSON which can then be output by the script.
I know it's an old Q but there are possibilities to access the keys and the values now (10.9+). In 10.9 you need to use Scripting libraries to make this run, in 10.10 you can use the code right inside the Script Editor:
use framework "Foundation"
set testRecord to {a:"aaa", b:"bbb", c:"ccc"}
set objCDictionary to current application's NSDictionary's dictionaryWithDictionary:testRecord
set allKeys to objCDictionary's allKeys()
repeat with theKey in allKeys
log theKey as text
log (objCDictionary's valueForKey:theKey) as text
end repeat
This is no hack or workaround. It just uses the "new" ability to access Objective-C-Objects from AppleScript.
Found this Q during searching for other topics and couldn't resist to answer ;-)
Update to deliver JSON functionality:
Of course we can dive deeper into the Foundation classes and use the NSJSONSerialization object:
use framework "Foundation"
set testRecord to {a:"aaa", b:"bbb", c:"ccc"}
set objCDictionary to current application's NSDictionary's dictionaryWithDictionary:testRecord
set {jsonDictionary, anError} to current application's NSJSONSerialization's dataWithJSONObject:objCDictionary options:(current application's NSJSONWritingPrettyPrinted) |error|:(reference)
if jsonDictionary is missing value then
log "An error occured: " & anError as text
else
log (current application's NSString's alloc()'s initWithData:jsonDictionary encoding:(current application's NSUTF8StringEncoding)) as text
end if
Have fun, Michael / Hamburg
If you just want to iterate through the values of the record, you could do something like this:
tell application "iPhoto"
repeat with value in (properties of album 1) as list
log value
end repeat
end tell
But it's not very clear to me what you really want to achieve.
Basically, what AtomicToothbrush and foo said. AppleScript records are more like C structs, with a known list of labels, than like an associative array, with arbitrary keys, and there is no (decent) in-language way to introspect the labels on a record. (And even if there were, you’d still have the problem of applying them to get values.)
In most cases, the answer is “use an associative array library instead.” However, you’re specifically interested in the labels from a properties value, which means we need a hack. The usual one is to force an error using the record, and then parse the error message, something like this:
set x to {a:1, b:2}
try
myRecord as string
on error message e
-- e will be the string “Can’t make {a:1, b:2} into type string”
end
Parsing this, and especially parsing this while allowing for non-English locales, is left as an exercise for the reader.
ShooTerKo's answer is incredibly helpful to me.
I'll bring up another possibility I'm surprised I didn't see anyone else mention, though. I have to go between AppleScript and JSON a lot in my scripts, and if you can install software on the computers that need to run the script, then I highly recommend JSONHelper to basically make the whole problem go away:
https://github.com/isair/JSONHelper

Listing of All Mysql Data Types and Syntax For All Settings

I'm looking for a listing of all MySQL data types and the available settings for each option for each data type.
After a bit of googling I couldn't find anything quite like that.
here you can find a quick summary of mysql data types, with range, attributes and default value
For completeness' sake, don't forget the MySQL documentation.
Although the list is broken across multiple pages, often with a lot of commentary in between, it's a useful resource when you need to check some aspect of a particular type. There are also overviews of the basic types, but again, there's a lot of cruft mixed in with it.
if anyone ever needs them as a json array:
"[\"TINYINT[(M)]\", \"SMALLINT[(M)]\", \"MEDIUMINT[(M)]\", \"INT[(M)]\", \"BIGINT[(M)]\", \"FLOAT(p)\", \"FLOAT[(M,D)]\", \"DOUBLE[(M,D)]\", \"DECIMAL[(M,[D])]\", \"BIT[(M)]\", \"CHAR[(M)]\", \"VARCHAR(M)\", \"TINYTEXT\", \"TEXT\", \"MEDIUMTEXT\", \"LONGTEXT\", \"BINARY[(M)]\", \"VARBINARY(M)\", \"TINYBLOB\", \"BLOB\", \"MEDIUMBLOB\", \"LONGBLOB\", \"ENUM(\\\"A1\\\",\\\"A2\\\",...)\", \"SET(\\\"A1\\\",\\\"A2\\\",...)\", \"DATE\", \"DATETIME\", \"TIME\", \"TIMESTAMP\", \"YEAR\"]"